Hackish way of referring to the postal service, analogizing it to a
very slow, low-reliability network. Usenet
sig blocks sometimes include a “Paper-Net:” header
just before the sender's postal address; common variants of this are
“Papernet” and “P-Net”. Note that the standard
netiquette guidelines discourage this practice as a
waste of bandwidth, since netters are quite unlikely to casually use postal
addresses. Compare voice-net,
snail-mail.